A fake IW329057 fails three checks: the serial number, the case back engraving, and the movement. No photo, no box, and no receipt proves a watch real. A watchmaker with the case back off proves more than any listing.
IWC reference numbers use the form IW plus six digits. The IW3290xx block belongs to the Aquatimer Automatic 42 family. The exact string IW329057 does not appear in IWC's public catalog list at the time of writing. Ask the seller for the full reference, the case number, and the serial number before you send money.
Check 1: Case number and serial number
IWC engraves two numbers on the case back. The case number and the serial number differ. A seller who sends one number, or two matching numbers, has not answered the question.
- Case number: identifies the case batch.
- Serial number: identifies the single watch.
- Request one photo showing both numbers with a dated card in the frame.
Check 2: Case back engraving
On a genuine Aquatimer the engraving has depth and sharp edges. Digits and letters sit on one baseline. The font stays consistent across the reference number, the numbers, and the SWISS MADE stamp. Replicas show shallow cuts, wide spacing, and a soft edge under a 10x loupe.
Check 3: Movement
A movement photo separates most replicas from the real item. Look at the rotor engraving, the jewel count, and the finish on the bridges. A 4 Hz balance beats 28,800 times per hour. Replica builds in the IW3290 range use a stock ETA, Sellita, or Seagull base with a printed rotor plate. Printed text rubs off. Engraved text does not. IWC does not publish a caliber list on every reference page, so confirm the caliber number with IWC or a watchmaker.
Check 4: Dial, hands, and bezel
Dial printing under a loupe has clean edges and no ink bleed. Check the date window position and the date font. Turn the bezel and count the clicks. The 12 o'clock marker should line up with the case center.
Check 5: Size and water resistance
The Aquatimer Automatic 42 measures 42 mm across the case with a 300 m water resistance rating. Weight changes with the bracelet or strap, so compare against a known example, not a guess. A pressure test is the only proof of water resistance.
Check 6: Papers, box, and price
A price far under the market range for the reference is the first flag. Ask for the warranty card, the service history, and the original invoice. Faked cards exist. Treat papers as a secondary signal, not proof.
What these checks cannot do
Good replicas copy dial text, case size, and rotor engraving. Two tests still need hands: a pressure test and a timing check on a Timegrapher. An IWC service center can confirm authenticity and issue paperwork.